Example in README has syntax errors (maybe)

[ip1981]

Adding a space after : in few places fix the problem:

yaml.scanner.ScannerError: while scanning a plain scalar
  in "<unicode string>", line 24, column 35:
            - compare: {raw_body: "", comparator:contains, expected: ' ... 
                                      ^
found unexpected ':'
  in "<unicode string>", line 24, column 45:
     ... mpare: {raw_body: "", comparator:contains, expected: 'Baltar' }  ... 
                                         ^
Please check http://pyyaml.org/wiki/YAMLColonInFlowContext for details.